<?php 
/** 
 * JsHttpRequest: PHP backend for JavaScript DHTML loader. 
 * (C) Dmitry Koterov, http://en.dklab.ru 
 * 
 * This library is free software; you can redistribute it and/or 
 * modify it under the terms of the GNU Lesser General Public 
 * License as published by the Free Software Foundation; either 
 * version 2.1 of the License, or (at your option) any later version. 
 * See http://www.gnu.org/copyleft/lesser.html 
 * 
 * Do not remove this comment if you want to use the script! 
 * Не удаляйте данный комментарий, если вы хотите использовать скрипт! 
 * 
 * This backend library also supports POST requests additionally to GET. 
 * 
 * @author Dmitry Koterov  
 * @version 5.x $Id$ 
 */ 

class JsHttpRequest 
{ 
    var $SCRIPT_ENCODING = "windows-1251"; 
    var $SCRIPT_DECODE_MODE = ''; 
    var $LOADER = null; 
    var $ID = null;     
     
    // Internal; uniq value. 
    var $_uniqHash;     
    // Internal: response content-type depending on loader type. 
    var $_contentTypes = array( 
        "script" => "text/javascript", 
        "xml"    => "text/plain", // In XMLHttpRequest mode we must return text/plain - stupid Opera 8.0. :( 
        "form"   => "text/html", 
        ""       => "text/plain", // for unknown loader 
    ); 
    // Internal: conversion to UTF-8 JSON cancelled because of non-ascii key. 
    var $_toUtfFailed = false; 
    // Internal: list of characters 128...255 (for strpbrk() ASCII check). 
    var $_nonAsciiChars = ''; 
    // Which Unicode conversion function is available? 
    var $_unicodeConvMethod = null; 

     
    /** 
     * Constructor. 
     *  
     * Create new JsHttpRequest backend object and attach it 
     * to script output buffer. As a result - script will always return 
     * correct JavaScript code, even in case of fatal errors. 
     */ 
    function JsHttpRequest($enc) 
    { 
        // QUERY_STRING is in form of: PHPSESSID=<sid>&a=aaa&b=bbb&JsHttpRequest=<id>-<loader> 
        // where <id> is a request ID, <loader> is a loader name, <sid> - a session ID (if present),  
        // PHPSESSID - session parameter name (by default = "PHPSESSID"). 
         
        // Parse QUERY_STRING. 
        if (preg_match('/^(.*)(?:&|^)JsHttpRequest=(?:(\d+)-)?([^&]+)((?:&|$).*)$/s', @$_SERVER['QUERY_STRING'], $m)) { 
            $this->ID = $m[2]; 
            $this->LOADER = strtolower($m[3]); 
            $_SERVER['QUERY_STRING'] = preg_replace('/^&+|&+$/s', '', preg_replace('/(^|&)'.session_name().'=[^&]*&?/s', '&', $m[1] . $m[4])); 
            unset( 
                $_GET['JsHttpRequest'], 
                $_REQUEST['JsHttpRequest'], 
                $_GET[session_name()], 
                $_POST[session_name()], 
                $_REQUEST[session_name()] 
            ); 
        } else { 
            $this->ID = 0; 
            $this->LOADER = 'unknown'; 
        } 
         
        // Detect Unicode conversion method. 
        $this->_unicodeConvMethod = function_exists('mb_convert_encoding')? 'mb' : (function_exists('iconv')? 'iconv' : null); 

        // Start OB handling early. 
        $this->_uniqHash = md5(microtime() . getmypid()); 
        ini_set('error_prepend_string', ini_get('error_prepend_string') . $this->_uniqHash); 
        ini_set('error_append_string',  ini_get('error_append_string') . $this->_uniqHash); 
        ob_start(array(&$this, "_obHandler")); 

        // Set up the encoding. 
        $this->setEncoding($enc); 

        // Check if headers are already sent (see Content-Type library usage). 
        // If true - generate a debug message and exit. 
        $file = $line = null; 
        $result = version_compare(PHP_VERSION, "4.3.0") < 0? headers_sent() : headers_sent($file, $line); 
        if ($result) { 
            trigger_error( 
                "HTTP headers are already sent" . ($line !== null? " in $file on line $line" : " somewhere in the script") . ". " 
                . "Possibly you have an extra space (or a newline) before the first line of the script or any library. " 
                . "Please note that JsHttpRequest uses its own Content-Type header and fails if " 
                . "this header cannot be set. See header() function documentation for more details", 
                E_USER_ERROR 
            ); 
            exit(); 
        } 
    } 


    /** 
     * string getJsCode() 
     *  
     * Return JavaScript part of the library. 
     */ 
    function getJsCode() 
    { 
        return file_get_contents(dirname(__FILE__).'/JsHttpRequest.js'); 
    } 


    /** 
     * void setEncoding(string $encoding) 
     *  
     * Set an active script encoding & correct QUERY_STRING according to it. 
     * Examples: 
     *   "windows-1251"          - set plain encoding (non-windows characters,  
     *                             e.g. hieroglyphs, are totally ignored) 
     *   "windows-1251 entities" - set windows encoding, BUT additionally replace: 
     *                             "&"         ->  "&amp;"  
     *                             hieroglyph  ->  &#XXXX; entity 
     */ 
    function setEncoding($enc) 
    { 
        // Parse an encoding. 
        preg_match('/^(\S*)(?:\s+(\S*))$/', $enc, $p); 
        $this->SCRIPT_ENCODING    = strtolower(!empty($p[1])? $p[1] : $enc); 
        $this->SCRIPT_DECODE_MODE = !empty($p[2])? $p[2] : ''; 
        // Manually parse QUERY_STRING because of damned Unicode's %uXXXX. 
        $this->_correctSuperglobals(); 
    } 

     
    /** 
     * string quoteInput(string $input) 
     *  
     * Quote a string according to the input decoding mode. 
     * If entities are used (see setEncoding()), no '&' character is quoted, 
     * only '"', '>' and '<' (we presume that '&' is already quoted by 
     * an input reader function). 
     * 
     * Use this function INSTEAD of htmlspecialchars() for $_GET data  
     * in your scripts. 
     */ 
    function quoteInput($s) 
    { 
        if ($this->SCRIPT_DECODE_MODE == 'entities') 
            return str_replace(array('"', '<', '>'), array('&quot;', '&lt;', '&gt;'), $s); 
        else 
            return htmlspecialchars($s); 
    } 
     

    /** 
     * Convert a PHP scalar, array or hash to JS scalar/array/hash. This function is  
     * an analog of json_encode(), but it can work with a non-UTF8 input and does not  
     * analyze the passed data. Output format must be fully JSON compatible. 
     *  
     * @param mixed $a   Any structure to convert to JS. 
     * @return string    JavaScript equivalent structure. 
     */ 
    function php2js($a=false) 
    { 
        if (is_null($a)) return 'null'; 
        if ($a === false) return 'false'; 
        if ($a === true) return 'true'; 
        if (is_scalar($a)) { 
            if (is_float($a)) { 
                // Always use "." for floats. 
                $a = str_replace(",", ".", strval($a)); 
            } 
            // All scalars are converted to strings to avoid indeterminism. 
            // PHP's "1" and 1 are equal for all PHP operators, but  
            // JS's "1" and 1 are not. So if we pass "1" or 1 from the PHP backend, 
            // we should get the same result in the JS frontend (string). 
            // Character replacements for JSON. 
            static $jsonReplaces = array( 
                array("\\", "/", "\n", "\t", "\r", "\b", "\f", '"'), 
                array('\\\\', '\\/', '\\n', '\\t', '\\r', '\\b', '\\f', '\"') 
            ); 
            return '"' . str_replace($jsonReplaces[0], $jsonReplaces[1], $a) . '"'; 
        } 
        $isList = true; 
        for ($i = 0, reset($a); $i < count($a); $i++, next($a)) { 
            if (key($a) !== $i) {  
                $isList = false;  
                break;  
            } 
        } 
        $result = array(); 
        if ($isList) { 
            foreach ($a as $v) { 
                $result[] = JsHttpRequest::php2js($v); 
            } 
            return '[ ' . join(', ', $result) . ' ]'; 
        } else { 
            foreach ($a as $k => $v) { 
                $result[] = JsHttpRequest::php2js($k) . ': ' . JsHttpRequest::php2js($v); 
            } 
            return '{ ' . join(', ', $result) . ' }'; 
        } 
    } 
     

         
    /** 
     * Internal methods. 
     */ 

    /** 
     * Parse & decode QUERY_STRING. 
     */ 
    function _correctSuperglobals() 
    { 
        // In case of FORM loader we may go to nirvana, everything is already parsed by PHP. 
        if ($this->LOADER == 'form') return; 
         
        // ATTENTION!!! 
        // HTTP_RAW_POST_DATA is only accessible when Content-Type of POST request 
        // is NOT default "application/x-www-form-urlencoded"!!! 
        // Library frontend sets "application/octet-stream" for that purpose, 
        // see JavaScript code. In PHP 5.2.2.HTTP_RAW_POST_DATA is not set sometimes;  
        // in such cases - read the POST data manually from the STDIN stream. 
        $rawPost = strcasecmp($_SERVER['REQUEST_METHOD'], 'POST') == 0? (isset($GLOBALS['HTTP_RAW_POST_DATA'])? $GLOBALS['HTTP_RAW_POST_DATA'] : @file_get_contents("php://input")) : null; 
        $source = array( 
            '_GET' => !empty($_SERVER['QUERY_STRING'])? $_SERVER['QUERY_STRING'] : null,  
            '_POST'=> $rawPost, 
        ); 
        foreach ($source as $dst=>$src) { 
            // First correct all 2-byte entities. 
            $s = preg_replace('/%(?!5B)(?!5D)([0-9a-f]{2})/si', '%u00\\1', $src); 
            // Now we can use standard parse_str() with no worry! 
            $data = null; 
            parse_str($s, $data); 
            $GLOBALS[$dst] = $this->_ucs2EntitiesDecode($data); 
        } 
        $GLOBALS['HTTP_GET_VARS'] = $_GET; // deprecated vars 
        $GLOBALS['HTTP_POST_VARS'] = $_POST; 
        $_REQUEST =  
            (isset($_COOKIE)? $_COOKIE : array()) +  
            (isset($_POST)? $_POST : array()) +  
            (isset($_GET)? $_GET : array()); 
        if (ini_get('register_globals')) { 
            // TODO? 
        } 
    } 


    /** 
     * Called in case of error too! 
     */ 
    function _obHandler($text) 
    { 
        // Check for error. 
        if (preg_match('{'.$this->_uniqHash.'(.*?)'.$this->_uniqHash.'}sx', $text)) { 
            $text = str_replace($this->_uniqHash, '', $text); 
        } 
         
        // Make a resulting hash. 
        if (!isset($this->RESULT)) { 
            $this->RESULT = isset($GLOBALS['_RESULT'])? $GLOBALS['_RESULT'] : null; 
        } 
        $encoding = $this->SCRIPT_ENCODING; 
        $result = array( 
            'id'   => $this->ID, 
            'js'   => $this->RESULT, 
            'text' => $text, 
        ); 
        if (function_exists('array_walk_recursive') && function_exists('json_encode') && $this->_unicodeConvMethod) { 
            $encoding = "UTF-8"; 
            $this->_nonAsciiChars = join("", array_map('chr', range(128, 255))); 
            $this->_toUtfFailed = false; 
            array_walk_recursive($result, array(&$this, '_toUtf8_callback'), $this->SCRIPT_ENCODING); 
            if (!$this->_toUtfFailed) { 
                // If some key contains non-ASCII character, convert everything manually. 
                $text = json_encode($result); 
            } else { 
                $text = $this->php2js($result); 
            } 
        } else { 
            $text = $this->php2js($result); 
        } 

        // Content-type header. 
        // In XMLHttpRequest mode we must return text/plain - damned stupid Opera 8.0. :( 
        $ctype = !empty($this->_contentTypes[$this->LOADER])? $this->_contentTypes[$this->LOADER] : $this->_contentTypes['']; 
        header("Content-type: $ctype; charset=$encoding"); 
         
        if ($this->LOADER != "xml") { 
            // In non-XML mode we cannot use plain JSON. So - wrap with JS function call. 
            // If top.JsHttpRequestGlobal is not defined, loading is aborted and  
            // iframe is removed, so - do not call dataReady(). 
            $text = ""  
                . ($this->LOADER == "form"? 'top && top.JsHttpRequestGlobal && top.JsHttpRequestGlobal' : 'JsHttpRequest')  
                . ".dataReady(" . $text . ")\n" 
                . ""; 
            if ($this->LOADER == "form") { 
                $text = '<script type="text/javascript" language="JavaScript"><!--' . "\n$text" . '//--></script>'; 
            } 
        } 

        return $text; 
    } 


    /** 
     * Internal function, used in array_walk_recursive() before json_encode() call. 
     * If a key contains non-ASCII characters, this function sets $this->_toUtfFailed = true, 
     * becaues array_walk_recursive() cannot modify array keys. 
     */ 
    function _toUtf8_callback(&$v, $k, $fromEnc) 
    { 
        if ($this->_toUtfFailed || strpbrk($k, $this->_nonAsciiChars) !== false) { 
            $this->_toUtfFailed = true; 
        } else { 
            $v = $this->_unicodeConv($fromEnc, 'UTF-8', $v); 
        } 
    } 
     

    /** 
     * Decode all %uXXXX entities in string or array (recurrent). 
     * String must not contain %XX entities - they are ignored! 
     */ 
    function _ucs2EntitiesDecode($data) 
    { 
        if (is_array($data)) { 
            $d = array(); 
            foreach ($data as $k=>$v) { 
                $d[$this->_ucs2EntitiesDecode($k)] = $this->_ucs2EntitiesDecode($v); 
            } 
            return $d; 
        } else { 
            if (strpos($data, '%u') !== false) { // improve speed 
                $data = preg_replace_callback('/%u([0-9A-F]{1,4})/si', array(&$this, '_ucs2EntitiesDecodeCallback'), $data); 
            } 
            return $data; 
        } 
    } 


    /** 
     * Decode one %uXXXX entity (RE callback). 
     */ 
    function _ucs2EntitiesDecodeCallback($p) 
    { 
        $hex = $p[1]; 
        $dec = hexdec($hex); 
        if ($dec === "38" && $this->SCRIPT_DECODE_MODE == 'entities') { 
            // Process "&" separately in "entities" decode mode. 
            $c = "&amp;"; 
        } else { 
            if ($this->_unicodeConvMethod) { 
                $c = @$this->_unicodeConv('UCS-2BE', $this->SCRIPT_ENCODING, pack('n', $dec)); 
            } else { 
                $c = $this->_decUcs2Decode($dec, $this->SCRIPT_ENCODING); 
            } 
            if (!strlen($c)) { 
                if ($this->SCRIPT_DECODE_MODE == 'entities') { 
                    $c = '&#' . $dec . ';'; 
                } else { 
                    $c = '?'; 
                } 
            } 
        } 
        return $c; 
    } 


    /** 
     * Wrapper for iconv() or mb_convert_encoding() functions. 
     * This function will generate fatal error if none of these functons available! 
     *  
     * @see iconv() 
     */ 
    function _unicodeConv($fromEnc, $toEnc, $v) 
    { 
        if ($this->_unicodeConvMethod == 'iconv') { 
            return iconv($fromEnc, $toEnc, $v); 
        }  
        return mb_convert_encoding($v, $toEnc, $fromEnc); 
    } 



    /** 
     * If there is no ICONV, try to decode 1-byte characters manually 
     * (for most popular charsets only). 
     */ 
      
    /** 
     * Convert from UCS-2BE decimal to $toEnc. 
     */ 
    function _decUcs2Decode($code, $toEnc) 
    { 
        if ($code < 128) return chr($code); 
        if (isset($this->_encTables[$toEnc])) { 
            // TODO: possible speedup by using array_flip($this->_encTables) and later hash access in the constructor. 
            $p = array_search($code, $this->_encTables[$toEnc]); 
            if ($p !== false) return chr(128 + $p); 
        } 
        return ""; 
    } 
     

    /** 
     * UCS-2BE -> 1-byte encodings (from #128). 
     */ 
    var $_encTables = array( 
        'windows-1251' => array( 
            0x0402, 0x0403, 0x201A, 0x0453, 0x201E, 0x2026, 0x2020, 0x2021, 
            0x20AC, 0x2030, 0x0409, 0x2039, 0x040A, 0x040C, 0x040B, 0x040F, 
            0x0452, 0x2018, 0x2019, 0x201C, 0x201D, 0x2022, 0x2013, 0x2014, 
            0x0098, 0x2122, 0x0459, 0x203A, 0x045A, 0x045C, 0x045B, 0x045F, 
            0x00A0, 0x040E, 0x045E, 0x0408, 0x00A4, 0x0490, 0x00A6, 0x00A7, 
            0x0401, 0x00A9, 0x0404, 0x00AB, 0x00AC, 0x00AD, 0x00AE, 0x0407, 
            0x00B0, 0x00B1, 0x0406, 0x0456, 0x0491, 0x00B5, 0x00B6, 0x00B7, 
            0x0451, 0x2116, 0x0454, 0x00BB, 0x0458, 0x0405, 0x0455, 0x0457, 
            0x0410, 0x0411, 0x0412, 0x0413, 0x0414, 0x0415, 0x0416, 0x0417, 
            0x0418, 0x0419, 0x041A, 0x041B, 0x041C, 0x041D, 0x041E, 0x041F, 
            0x0420, 0x0421, 0x0422, 0x0423, 0x0424, 0x0425, 0x0426, 0x0427, 
            0x0428, 0x0429, 0x042A, 0x042B, 0x042C, 0x042D, 0x042E, 0x042F, 
            0x0430, 0x0431, 0x0432, 0x0433, 0x0434, 0x0435, 0x0436, 0x0437, 
            0x0438, 0x0439, 0x043A, 0x043B, 0x043C, 0x043D, 0x043E, 0x043F, 
            0x0440, 0x0441, 0x0442, 0x0443, 0x0444, 0x0445, 0x0446, 0x0447, 
            0x0448, 0x0449, 0x044A, 0x044B, 0x044C, 0x044D, 0x044E, 0x044F, 
        ), 
        'koi8-r' => array( 
            0x2500, 0x2502, 0x250C, 0x2510, 0x2514, 0x2518, 0x251C, 0x2524, 
            0x252C, 0x2534, 0x253C, 0x2580, 0x2584, 0x2588, 0x258C, 0x2590, 
            0x2591, 0x2592, 0x2593, 0x2320, 0x25A0, 0x2219, 0x221A, 0x2248, 
            0x2264, 0x2265, 0x00A0, 0x2321, 0x00B0, 0x00B2, 0x00B7, 0x00F7, 
            0x2550, 0x2551, 0x2552, 0x0451, 0x2553, 0x2554, 0x2555, 0x2556, 
            0x2557, 0x2558, 0x2559, 0x255A, 0x255B, 0x255C, 0x255d, 0x255E, 
            0x255F, 0x2560, 0x2561, 0x0401, 0x2562, 0x2563, 0x2564, 0x2565, 
            0x2566, 0x2567, 0x2568, 0x2569, 0x256A, 0x256B, 0x256C, 0x00A9, 
            0x044E, 0x0430, 0x0431, 0x0446, 0x0434, 0x0435, 0x0444, 0x0433, 
            0x0445, 0x0438, 0x0439, 0x043A, 0x043B, 0x043C, 0x043d, 0x043E, 
            0x043F, 0x044F, 0x0440, 0x0441, 0x0442, 0x0443, 0x0436, 0x0432, 
            0x044C, 0x044B, 0x0437, 0x0448, 0x044d, 0x0449, 0x0447, 0x044A, 
            0x042E, 0x0410, 0x0411, 0x0426, 0x0414, 0x0415, 0x0424, 0x0413, 
            0x0425, 0x0418, 0x0419, 0x041A, 0x041B, 0x041C, 0x041d, 0x041E, 
            0x041F, 0x042F, 0x0420, 0x0421, 0x0422, 0x0423, 0x0416, 0x0412, 
            0x042C, 0x042B, 0x0417, 0x0428, 0x042d, 0x0429, 0x0427, 0x042A       
        ), 
    ); 
} 
?>